<template>
  <el-breadcrumb class="app-breadcrumb" separator="/">
    <transition-group name="breadcrumb">
      <el-breadcrumb-item v-for="(item,index) in levelList" :key="item.path">
        <span v-if="item.redirect==='noRedirect'||index==levelList.length-1" class="no-redirect">{{
          item.meta.title }}</span>
        <a v-else @click.prevent="handleLink(item)">{{ item.meta.title }}</a>
      </el-breadcrumb-item>
    </transition-group>
  </el-breadcrumb>
</template>

<script>
import pathToRegexp from 'path-to-regexp';

export default {
    data () {
        return {
            levelList: null
        };
    },
    watch: {
        $route () {
            this.getBreadcrumb();
        }
    },
    created () {
        this.getBreadcrumb();
    },
    methods: {
        getBreadcrumb () {
        // only show routes with meta.title
            let matched = this.$route.matched.filter(item => item.meta && item.meta.title);
            const first = matched[0];

            if (!this.isDashboard(first)) {
                matched = [{path: '/home', redirect: '/home', meta: { title: '首页' }}].concat(matched);
            }

            this.levelList = matched.filter(item => item.meta && item.meta.title && item.meta.breadcrumb !== false);
        },
        isDashboard (route) {
            const name = route && route.name;
            if (!name) {
                return false;
            }
            return name.trim().toLocaleLowerCase() === 'Home'.toLocaleLowerCase();
        },
        pathCompile (path) {
        // To solve this problem https://github.com/PanJiaChen/vue-element-admin/issues/561
            const { params } = this.$route;
            var toPath = pathToRegexp.compile(path);
            return toPath(params);
        },
        handleLink (item) {
            const { redirect, path } = item;
            if (redirect) {
                this.$router.push(redirect);
                return;
            }
            this.$router.push(this.pathCompile(path));
        }
    }
};
</script>

<style lang="scss" scoped>
  .app-breadcrumb.el-breadcrumb {
    display: inline-block;
    font-size: 14px;
    /*line-height: 46px;*/
    margin-left: 32px;
    vertical-align: middle;
    .no-redirect {
      color: #666;
      cursor: text;
    }
  }
</style>
